If the input vswr of the amplifier is elevated on 30M your exciter may be
reducing drive power to prevent damage. Reduced drive power = reduced output
power.
You can use a small tuner to reduce the input vswr if this is the case.
73,
Gerald K5GW
In a message dated 1/19/2009 3:50:45 P.M. Central Standard Time,
w2wg@comcast.net writes:
I have a very early AL80B. It will produce 500-700W key down on all
bands--except 30m. Of course you don't need much of an amp on 30m with the
limit being 200W, but I am curious as to what the problem is. The
suggested Ameritron tuning chart shows the load control at 0, which is
presumably plates fully meshed. That indeed is where it wants to be loaded
on 30m, but it struggles to put out 150w, regardless of how hard you drive
it. Neither plate current or grid current is excessive. The amp has a
30m/20m selection on the bandswitch and I get 700W out on 20m. What would
the problem likely be. Has anyone else run into this on 30m? I bought this
amp used around 1995 and it has always had this behavior.
Bob W2WG
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